title: Measurement of macrophage-mediated cytotoxicity against adherent and non-adherent target cells by release of 11 indium-oxine.
abstract: This report describes the utilization of 111 indium-oxine chelate ([111In]Ox) for studies of macrophage-mediated cytotoxicity. [111In]Ox efficiently labeled both non-adherent and adherent tumor targets with no decrease in cell viability. Spontaneous release of intracellularly incorporated [111In]Ox was very slow (0.25-0.50%/h) from most targets, making isotope-release assays of at least 48 h feasible. In addition, released [111In]Ox was not reutilized. In contrast to its low spontaneous release from intact cells, incorporated [111In]Ox was rapidly released from tumor targets after interaction with activated macrophages. Levels of [111In]Ox released in response to cytolytic macrophages correlated well with those observed for the 51Cr and [3H]TdR radiolabels. Therefore, [111In]Ox can be utilized for relatively short-term (less than 20h) assays with lymphoma targets, as well as for longer-term assays with adherent cells. This should facilitate the testing, with the same radioisotope-release assay, of a wide range of tumor targets for susceptibility to macrophage-mediated cytotoxicity.
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002470:Cell Survival; D003602:Cytotoxicity, Immunologic; D005260:Female; D006912:Hydroxyquinolines / Q000378:metabolism*; D007204:Indium / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009374:Neoplasms, Experimental / Q000276:immunology*; D015125:Oxyquinoline / Q000378:metabolism*; D011868:Radioisotopes
chemical_list: D006912:Hydroxyquinolines; D008070:Lipopolysaccharides; D011868:Radioisotopes; D007204:Indium; D015125:Oxyquinoline